One of the disadvantages of digital television (DTV) systems such as set-top boxes (STBs) is that initial channel acquisition and channel change take more time than the analogous functions in analog TV. The longer channel acquisition and channel change times are due largely to the complexity of the decoding process for the live DTV signal. A typical DTV decoding involves numerous functions and processes including demodulation locking, forward-error-correction (FEC) locking, transport stream decryption and filtering, MPEG video sequence header parsing and decoding, frame buffering and display. Because of the complexity of the decoding process, some STBs have about a two to three second delay in channel changes.
Personal video recorder (PVR) systems offer consumers a hard disk-based recording system analogous to analog video cassette recorder (VCR) systems. PVR systems can digitally record live television programs, while offering the versatility of select playback and associated special features. The viewer can take advantage of trick play features such as pause/still, fast forward, slow forward, rewind, slow reverse, skip, etc. Existing PVR systems are capable of performing recording functions on both digital and analog channels. In a typical PVR system, video is generally looped through a playback buffer (typically RAM) before it is sent to the MPEG decoder during any live decoding so that a pause can be seamless. This extra cycle through a buffer increases the time it takes for a user to change channels.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.